Frequently Asked Questions

Get answers to your most frequently asked questions about Gablofen® (baclofen injection)

What is Gablofen® (baclofen injection)?

Gablofen® is a muscle relaxant and antipastic gamma-aminobutyric acid (GABA) ergic agonist. Gablofen’s precise mechanism of action is not fully understood. Gablofen® inhibits both monosynaptic and polysynaptic reflexes at the spinal level, possibly by decreasing excitatory neurotransmitter release from primary afferent terminals, although actions at supraspinal sites may also occur and contribute to its clinical effect. Baclofen is a structural analog of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA), and may exert its effect by stimulation of the GABAB receptor subtype.

When Gablofen® is introduced directly into the intrathecal space, it permits effective CSF concentrations to be achieved with resultant plasma concentrations 100 times less than those occurring with oral administration.2

Who is Gablofen® appropriate for?

Gablofen® is indicated for use in the management of severe spasticity of cerebral or spinal origin in adult and pediatric patients aged 4 years and above. It must be reserved for patients unresponsive to oral baclofen therapy, or those who experience intolerable central nervous system side effects at effective doses. Patients should first respond to a screening dose of intrathecal baclofen prior to consideration for long term infusion via an implantable pump. Patients with spasticity due to traumatic brain injury should wait at least one year after injury before considering Gablofen® therapy.2

If my patient fails oral baclofen, what may be the next step?

Gablofen® should be reserved for patients unresponsive to oral baclofen therapy or those who experience intolerable central nervous system side effects at effective doses. After a patient fails oral baclofen, it may be time to consider intrathecal baclofen therapy. This is an important decision. Patients should first respond to a screening dose of intrathecal baclofen prior to consideration for long-term infusion via an implantable pump. A Gablofen® screening dose is available in a prefilled syringe.2

What if I am unsure a patient will respond positively to Gablofen®?

Patients should first respond to a screening dose of intrathecal baclofen prior to consideration for long term infusion via an implantable pump. The Gablofen® screening dose is used to determine if a patient will demonstrate a positive clinical response to Gablofen®.2

How is Gablofen® administered to patients?

Gablofen® is intended for use by the intrathecal route in single bolus test doses (via spinal catheter or lumbar puncture) and, for chronic use, only with the Medtronic SynchroMed II Programmable Pump or other pumps labeled for intrathecal administration of Gablofen®. Gablofen® is available in prefilled syringes and factory-sealed vials.2

SynchroMed is a registered trademark of Medtronic, Inc.

For which intrathecal pumps is Gablofen® approved?

Gablofen® is FDA-approved for use in pumps labeled for intrathecal administration of Gablofen®, including the Medtronic SynchroMed® II Programmable Pump.2 Clinicians should refer to the pump manufacturer’s manual and follow the specific instructions and precautions for programming the pump and/or refilling the reservoir.

SynchroMed is a registered trademark of Medtronic, Inc.

What concentrations are available?

Gablofen® is available in a screening dose of 50 mcg/mL. There are also 3 refill concentrations: 500 mcg/mL, 1,000 mcg/mL, and 2,000 mcg/mL concentrations in both prefilled syringes and factory-sealed vials.2

All packaging options are manufactured under Current Good Manufacturing Practices (CGMP). You can use the Concentration Calculator to determine the days between pump refills at certain concentrations of Gablofen®. Please note the Concentration Calculator is only an aid and does not replace medical expertise.

Are Gablofen® and Lioresal® therapeutically equivalent?

Yes, Gablofen® is listed in the FDA Orange Book as an AP-rated intrathecal baclofen at the 50 mcg/mL, 500 mcg/mL, and 2,000 mcg/mL concentrations. Gablofen® can be substituted for Lioresal at those particular concentrations.1

Gablofen® is also available in the exclusive FDA-approved 1,000 mcg/mL concentration. Lioresal is not available in a 1,000 mcg/mL concentration.1 Lioresal is a registered trademark of Medtronic, Inc.

What is the shelf life of Gablofen®?

Gablofen® prefilled syringes and factory-sealed vials have a shelf life of 3 years. Gablofen does not require refrigeration. Do not freeze.2

Indications and Usage

Gablofen® (baclofen injection) is a gamma-aminobutyric acid (GABA) ergic agonist indicated for use in the management of severe spasticity of cerebral or spinal origin in adult and pediatric patients age 4 years and above.

Gablofen should be reserved for patients unresponsive to oral baclofen therapy, or those who experience intolerable central nervous system side effects at effective doses.

Patients should first respond to a screening dose of intrathecal baclofen prior to consideration for long term infusion via an implantable pump.

Spasticity due to traumatic brain injury: wait at least one year after injury before considering Gablofen therapy.

IMPORTANT RISK INFORMATION

WARNING: DO NOT DISCONTINUE ABRUPTLY

See full prescribing information for complete boxed warning

Abrupt discontinuation of intrathecal baclofen, regardless of the cause, has resulted in sequelae that include high fever, altered mental status, exaggerated rebound spasticity, and muscle rigidity, that in rare cases has advanced to rhabdomyolysis, multiple organ-system failure and death.

Prevention of abrupt discontinuation of intrathecal baclofen requires careful attention to programming and monitoring of the infusion system, refill scheduling and procedures, and pump alarms. Patients and caregivers should be advised of the importance of keeping scheduled refill visits and should be educated on the early symptoms of baclofen withdrawal. Special attention should be given to patients at apparent risk (e.g. spinal cord injuries at T-6 or above, communication difficulties, history of withdrawal symptoms from oral or intrathecal baclofen). Consult the technical manual of the implantable infusion system for additional post-implant clinician and patient information.

CONTRAINDICATIONS

Hypersensitivity to baclofen.

Do not use Gablofen for intravenous, intramuscular, subcutaneous or epidural administration.

WARNINGS AND PRECAUTIONS

Risk of life-threatening overdose during pump refills. Use extreme caution when filling the Medtronic SynchroMed® II Programmable Pump which is equipped with an injection port that allows direct access to the intrathecal catheter. Direct injection into the catheter through the catheter access port may cause a life-threatening overdose.

Use only with Medtronic SynchroMed® II Programmable Pump (or other pumps labeled for intrathecal administration of Gablofen (baclofen injection)).

Potential for contamination due to non-sterile external surface of prefilled syringe. Although the drug solution and pathway in the Gablofen prefilled syringes are sterile, the external surface of the prefilled syringes (all strengths, including the 50 mcg/mL strength) are non-sterile and have the potential to lead to contamination and consequent adverse reactions. The use of Gablofen prefilled syringe in an aseptic setting (e.g., operating room) to fill sterile intrathecal pumps prior to implantation in patients is not recommended, unless the external surface of the prefilled syringe is treated to ensure sterility. Gablofen supplied in vials may be used with conventional aseptic technique to fill intrathecal pumps prior to implantation.

Resuscitative equipment and trained staff must be available during screening dose, dose titration, and refills due to the potential life-threatening CNS depression, cardiovascular collapse, and/or respiratory failure.

Use with caution in patients with psychotic disorders, schizophrenia or confusional states as it may exacerbate condition(s).

Fatalities have been reported with intrathecal baclofen use.

Caution should be used in patients with a history of autonomic dysreflexia.

Presence of infection may increase the risk of surgical complication and complicate dosing of Gablofen.

May cause drowsiness: use caution in operation of automobiles, dangerous machinery and activity that may be hazardous by decreased alertness. Other CNS depressants and alcohol may add to this effect.

Potential development of intrathecal mass formation. Clinicians should monitor for signs and symptoms of new neurologic symptoms including the use of imaging diagnostic modalities.

Oral baclofen use has been associated with a dose-related increase in incidence of ovarian cysts.

ADVERSE REACTIONS

Serious Adverse Reactions

Sudden withdrawal of Gablofen can result in serious complications that include high fever, confusion, muscle stiffness, multiple organ-system failure, and death. Inform patients that early symptoms of Gablofen withdrawal may include increased spasticity, itching, and tingling of extremities. If Gablofen withdrawal or a pump malfunction is suspected, patients should be brought immediately to a hospital for assessment and treatment.

Gablofen overdose may occur suddenly or insidiously, and symptoms may include confusion, drowsiness, lightheadedness, dizziness, slow or shallow breathing, seizures, loss of muscle tone, loss of consciousness, and coma.